Means for manufacturing brush handles



Dec. 4,1934. R. IZAWA 1,983,035

MEANS FOR MANUFACTURING BRUSH HANDLES Filed Aug. 31, 1933 C mmlNVE TOR ATTORNEY Patented Dec. 4, 1934 MEANS For: MANUFACTURING BRUSH, p HANDLES v n 1 Ri ichiro Izawa, Kyoto, Japan I j Applicationnugust 31, 1933, Serial nejssmws 1 Claim. (01. 18-42) This invention 1 relates; to improvements in means -f.or :1:1manufacturing brush handles, and more .particularlyrtoothbrush handles, the. object .ofitheinyention beingitoiprovide means whereby '5. brush handles having. flexible, bristle-receiving portions may be quickly and economically manufactured.

1 I :In Patent .No.1,466,723, granted to me under dateof September 4; 1923,31 have disclosed a toothbrush in which the bristle end of the brush handle or back is made up of a plurality of separate members held together and to the main portion of the'handle by means of a thin curved strip of resilient metal, thereby to impart flexibility to the forward end ofthebrush. 1

The principal object of the present invention is to provide a machine whereby brushes of the type disclosed in my said patent may be produced in commercially practical numbers.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists in the novel features of construction herein described and particularly pointed out in the claim.

1,25 In the drawing accompanying this specification,

Fig. 1 is a perspective view illustrating the upper and lower die members embodying the features of the present invention;

Fig. 2 is a transverse sectional view through the .1330 knife-carrying portion of the die, taken approximately on the line II--II of Fig. 3;

Fig. 3 is a longitudinal sectional view through the said knife-carrying portion, taken approximately on the line IIIIII of Fig. 2;

Fig. 4 is a perspective vew of the knife-carrying block; and

Fig. 5 is a perspective view of a device for holding the brush handle for insertion of the resilient strip.

"" Referring to the drawing, the invention comprises a pair of die members or blocks 1 and 2, preferably formed of a metal which is a good heat conductor, each having formed in one surface thereof a pair of longitudinally extending grooves f or depressions 3 and 4 the configuration of said grooves being such that when the die members are broughttogether with their grooved surfaces in juxtaposition the complementary groove por- MEO tions will form a mold of the desired shape. One

of the die blocks, as for instance the block 1 is provided adjacent its opposite ends with perforations 5 and the companion block carries pins 6 adapted to enter said perforations and thus 1. constitute guides for ensuring the accurate alinement of-w the complementary mold-forming v grooves. w ,r i A One of the blocks, as for instance the block 2,

,is provided in the forwardportion of each of its grooves 4 with transversely extending ribs '7 havingknife edges. As shown herein, the ribs are formed integral with the block, the knife edges being in the plane of the surface of the block.

It willreadily be understood, however, that, if found desirable or convenient, the ribs may be formed as separate members and of a different material from that ofthe block and inserted in kerfs formedin the block. 1

In the companion block 1, the bottom wall of i the forward portion of each of the grooves 3 is -cut out thereby forming; open slots through the entire thickness of the block. The block lis further cut away at the under surface of its forward end to form a seat for the reception of a knifecarrying plate 8, on which are mounted a series of spaced knives 9 for each groove of the block, the spaces between the knives being such that when the die blocks are placed in juxtaposition with the plate 8 inserted in the block 1 the edges of the knives 9 will be in alinement with the edges ,30 of the ribs 7. The knife-spacing blocks 10 carried by the plate 8 are of such dimensions and form that, with the knives supported between them, they will completely fill the respective slots inthe block 1. The length of the knives is prefg5 erably slightly greater than the width of the spacing blocks 10, so that the ends of the knives extend beyond the sides of the blocks, as shown in Fig. 4, the side walls of the slots in the block 1 being provided with vertical guide grooves for receiving the ends of the knives, as indicated in dotted lines at 11 in Fig. 2. The plate 8 is provided near one edge thereof with perforations 12 in position to receive the ends of the guide pins 6 carried by the block 2. The knives 9 are cut out at their central portions to provide depressions 13 to accommodate the metallic spring inserted in the brush handle so that the spring will not be cut during the operation of the dies on the toothbrush handle as hereinafter described. 1

In Fig. 5, I have shown a convenient tool for holding the blank from which the handle is to be formed during the preliminary operation of inserting the resilient metal strip. The said tool comprises a pair of elongated blocks 16 and 17, 5 preferably hinged together along one edge as indicated at 18. Each of said blocks is provided with a longitudinally extending groove 19 so located that when theblocks are swung into superimposed position the complementary groove will no form a cavity of suflicient dimensions to house the brush handle 14 in which the metal strip 15 is to be inserted. One of the blocks, as for instance the block 16, is provided with perforations 20, and the other block 1'7 with guide pins 21, in order to ensure accurate alignment of the grooves 19 when the blocks are swung by means of the handles 22 into superimposed position.

The brush handle 14 is first heated, for instance by immersion in hot water, and placed in one of the grooves 19, the tool 16, 17 having been in the meantime heated to a temperature approximately the same as that of the brush handle, whereby, when the blocks 16 and 17 are swung together the said handle 14 will be maintained in a condition sufficiently plastic to permit the metal strip 15 to be readily inserted therein, said strip being pushed lengthwise into the handle until it is completely embedded therein. The handle thus prepared is then removed from the tool 16, 1'7 and placed in one of the grooves 3 in the die block 1, in which the knife-carrying plate 8 has previously been placed in position for operation. The block 2 is then superimposed on the block 1 with its guide pins 6 in engagement with the holes 5, both of the blocks 1 and 2' having also been heated to a temperature sufficient to maintain the brush handle in a partially plastic condition. The blocks 1 and 2 are then subjected to sufiicient pressure to bring their opposing surfaces into abutting relation. As will readily be seen, this operation will carry the edges of the knives 9 into contact with the knife edges of the ribs '7, so that the material of the brush handle 14 in that portion of the mold will be completely severed by said knife edges, while the me tallic strip 15 rests in the depressions 13 and thus remains intact. Upon removal from the die blocks, the brush handle is ready to receive the bristles in the usual way.

The knife spacing blocks 10 may be formed integral with the plate 8, shown in the drawing or may be made up of individual members secured in any suitable manner on said plate. The knives 9 also may be secured in position in any suitable manner, as for instance by brazing.

While I have described in detail the invention herein illustrated, it will of course be understood that I do not desire to limit my invention to the precise features of construction herein set forth, as I am aware that many mechanicalchanges and modifications may be made therein without departing from the spirit and scope of the appended claim.

What I claim and desire to secure by Letters Patent is:

A device for forming brush backs, comprising a pair of die-blocks having complementary grooves coacting to form a mold, a series of ribs carried by one of said blocks within a portion of its groove and extending transversely thereof, the

other die being provided with an open slot at that portion of its groove opposite the rib-carrying portion of the companion block, and a member removably carried by said slotted block and having a series of ribs extending into said slot, i'. 

